Objective:To discuss the effect of modified ultrafiltration combined with sequential infusion of blood products, such as platelets and cryoprecipitation, on perioperative coagulation function in neonates undergoing cardiovascular surgery under extracorporeal circulation.Methods:A retrospective analysis was performed on 83 neonates who underwent cardiovascular surgery from January 2017 to December 2019. They were divided into the control group (conventional ultrafiltration, 51 cases) and the treatment group (modified ultrafiltration + sequential infusion of blood products, 32 cases).Results:The age of treatment group was significantly younger than that of the control group ( P<0.05). The extracorporeal circulation time of the treatment group was significantly longer than that of the control group. Compared with the preoperative data, post-APTT, post-PT and post-INR were increased significantly in the control group, platelet count and FIB were decreased significantly ( P<0.01), while there was no significant difference in the treatment group. Compared with the treatment groups, post-APTT, post-PT and post-INR were significantly increased in the control group, and postoperative platelet count and FIB were significantly decreased ( P<0.05). The drainage of control group was significantly higher than that of the treatment group at 12 h and 24 h after surgery ( P<0.01). Conclusion:The application of modified ultrafiltration combined with sequential infusion of blood products can significantly improve perioperative coagulation and reduce mediastinal bleeding in neonatal after cardiovascular surgery.